Cosmopolitans argue that the account of human rights and distributive justice in John Rawls's The Law of Peoples is incompatible with his argument for liberal justice. Rawls should extend his account of liberal basic liberties and the guarantees of distributive justice to apply to the world at large. This essay defends Rawls's grounding of political justice in social cooperation. The Law of Peoples is drawn up to provide principles of foreign policy for liberal peoples. Human rights are among the necessary conditions for social cooperation, and so long as a decent people respect human rights, a common good, and the Law of Peoples, it is not the role of liberal peoples to impose upon well-ordered decent peoples liberal liberties they cannot endorse. Moreover, the difference principle is not an allocative or alleviatory principle, but applies to design property and other basic social institutions necessary to economic production, exchange and consumption. It presupposes political cooperation—a legislative body to actively apply it, and a legal system to apply it to. There is no feasible global state or global legal system that could serve these roles. Finally, the difference principle embodies a conception of democratic reciprocity that is only appropriate to cooperation among free and equal citizens who are socially productive and politically autonomous. a Footnotesa I am grateful to K. C. Tan for many helpful discussions and criticisms of this essay. I am also grateful to the other contributors to this volume for their comments, and to Ellen Paul for her many helpful suggestions in preparing the final version of this essay.